[qsdf38100]

Note that colors we can perceive aren’t all in the rainbow. There’s no pink in the rainbow. That’s because pink is what is left when you take white light and remove the green part. It’s minus green. There’s no wavelength that corresponds to pink.

[Koshkin]

So what? A mix of wavelengths is just as real as a single wavelength. More to the point, colors are merely perceptions (artifacts of consciousness) which can be caused by a variety of factors.